I am creating an experiment in which participants will be presented with the following events:

Fixation Cross for 500ms

Pictures from a stimulus list for 250ms

A Cue from a stimulus list for 100ms

An ISI of 5000ms

A Response Box

A Rating screen

Repeat for the 24 pictures in the list

Then I am repeat the same grouping but with pictures from a different stimulus list and cues from a different stimulus.

I cannot however find a way to randomize the trials within this block so that I have have, for example, 2 pictures from stimulus set 1 with cues from set 1 followed by 4 images from stimulus set 2 and cues from set 2.